support tortoise_number metric

controllers/tortoise_controller.go

@@ -43,6 +43,7 @@ import (
 	"github.com/mercari/tortoise/pkg/annotation"
 	"github.com/mercari/tortoise/pkg/deployment"
 	"github.com/mercari/tortoise/pkg/hpa"
+	"github.com/mercari/tortoise/pkg/metrics"
 	"github.com/mercari/tortoise/pkg/recommender"
 	"github.com/mercari/tortoise/pkg/tortoise"
 	"github.com/mercari/tortoise/pkg/vpa"
@@ -87,6 +88,7 @@ func (r *TortoiseReconciler) Reconcile(ctx context.Context, req ctrl.Request) (_
 		if apierrors.IsNotFound(err) {
 			// Probably deleted already and finalizer is already removed.
 			logger.V(4).Info("tortoise is not found", "tortoise", req.NamespacedName)
+			metrics.RecordTortoise(tortoise, true)
 			return ctrl.Result{}, nil
 		}
 
@@ -103,9 +105,12 @@ func (r *TortoiseReconciler) Reconcile(ctx context.Context, req ctrl.Request) (_
 		if err := r.TortoiseService.RemoveFinalizer(ctx, tortoise); err != nil {
 			return ctrl.Result{}, fmt.Errorf("remove finalizer: %w", err)
 		}
+		metrics.RecordTortoise(tortoise, true)
 		return ctrl.Result{RequeueAfter: r.Interval}, nil
 	}
 
+	metrics.RecordTortoise(tortoise, false)
+
 	defer func() {
 		if tortoise == nil {
 			logger.Error(reterr, "get error during the reconciliation, but cannot record the event because tortoise object is nil", "tortoise", req.NamespacedName)

pkg/metrics/metrics.go

@@ -1,6 +1,7 @@
 package metrics
 
 import (
+	"github.com/mercari/tortoise/api/v1beta2"
 	"github.com/prometheus/client_golang/prometheus"
 	"sigs.k8s.io/controller-runtime/pkg/metrics"
 )
@@ -55,6 +56,11 @@ var (
 		Name: "proposed_memory_request",
 		Help: "recommended memory request (byte) that tortoises propose",
 	}, []string{"tortoise_name", "namespace", "container_name", "controller_name", "controller_kind"})
+
+	TortoiseNumber = prometheus.NewGaugeVec(prometheus.GaugeOpts{
+		Name: "tortoise_number",
+		Help: "the number of tortoise",
+	}, []string{"tortoise_name", "namespace", "controller_name", "controller_kind", "update_mode", "tortoise_phase"})
 )
 
 func init() {
@@ -72,3 +78,18 @@ func init() {
 		ProposedMemoryRequest,
 	)
 }
+
+func RecordTortoise(t *v1beta2.Tortoise, deleted bool) {
+	value := 1.0
+	if deleted {
+		value = 0
+	}
+	TortoiseNumber.WithLabelValues(
+		t.Name,
+		t.Namespace,
+		t.Spec.TargetRefs.ScaleTargetRef.Name,
+		t.Spec.TargetRefs.ScaleTargetRef.Kind,
+		string(t.Spec.UpdateMode),
+		string(t.Status.TortoisePhase),
+	).Set(value)
+}